660 MW循环流化床锅炉深度调峰背景下分离器入口烟道积灰模拟研究  

Simulation Study on Ash Accumulation in Separator Inlet Flue of 660 MW Circulating Fluidized Bed Boiler under Deep Peak Shaving

作　　者：周世豪 刘海玉[1] 谢玉婷 金燕[1] ZHOU Shihao;LIU Haiyu;XIE Yuting;JIN Yan(College of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan,China 030024)

机构地区：[1]太原理工大学电气与动力工程学院,山西太原030024

出　　处：《热能动力工程》2024年第7期115-122,共8页Journal of Engineering for Thermal Energy and Power

基　　金：山西省重点研发计划项目(201903D321075)。

摘　　要：针对循环流化床锅炉在低负荷运行时分离器入口烟道出现严重积灰,影响锅炉正常运行的问题,以某660 MW循环流化床锅炉为研究对象,通过数值模拟的方法,分析了低负荷下锅炉内部流场的分布特征和飞灰沉积特性,并探究了入口速度和颗粒粒径对飞灰沉积的影响规律。模拟结果表明:在烟气从炉膛流到分离器入口烟道过程中,入口烟道底部会产生一个涡流区,小粒径的飞灰更易沉积在涡流区,而中、大粒径飞灰更易沉积在烟道后半部分;粒径分布相同条件下,飞灰沉积率随着入口速度的增大而减小,且30%负荷的沉积率是100%负荷时的16.15倍;当入口速度大于1.95 m/s,沉积有较为明显的改善;飞灰粒径越大,沉积率越大,当粒径超过80μm时,沉积率呈指数级增长。Aiming at the problem of serious ash accumulation in the inlet flue of the separator when the circulating fluidized bed(CFB)boiler was running at low load,which affected the normal operation of the boiler,taking a 660 MW circulating fluidized bed boiler as the research object,the distribution characteristics of the internal flow field and fly ash deposition characteristics of the boiler at low load were analyzed by numerical simulation method,and the influence of inlet velocity and particle size on fly ash deposition was explored.The simulation results show that when the flue gas flows from the furnace to the inlet flue of the separator,a vortex zone will be generated at the bottom of the inlet flue.Fly ash with small particle size is more likely to be deposited in the vortex area,while fly ash with medium and large particle sizes is more likely to be deposited in the back half of the flue.Under the same particle size distribution,the fly ash deposition rate decreases with the increase of inlet velocity,and the deposition rate at 30%load is 16.15 times that at 100%load.When the inlet velocity is greater than 1.95 m/s,the deposition rate is significantly improved.The larger the particle size of fly ash,the greater the deposition rate.When the particle size exceeds 80μm,the deposition rate increases exponentially.

关 键 词：循环流化床锅炉 深度调峰 烟道积灰 DDPM模型 

分 类 号：TK221[动力工程及工程热物理—动力机械及工程]